Every file created in ASM gets a system-generated filename, otherwise known as a fully qualified filename (FQFN). The fully qualified filename represents a complete path name in the ASM file system. An example of a fully qualified filename is:

+dgroup2/sample/controlfile/Current.256.541956473

You can use the fully qualified filename to reference (read or retrieve) an ASM file. ASM generates a fully qualified filename upon any request to create a file. A creation request cannot specify a fully qualified filename. Instead, it uses a simpler syntax to specify a file, such as an alias or just a disk group name. ASM then creates the file, placing it in the correct ASM “path” according to file type, and then assigns an appropriate fully qualified filename. If you specify an alias in the creation request, ASM also creates the alias so that it references the fully qualified filename.

FQFN are generally long and awkward, therefore, to make file-naming convention easier to remember the ASM Alias name format was introduced. ASM Aliases are essentially in hierarchical directory format, similar to the filesystem hierarchy. Alias names specify a disk group name, but instead of a file and incarnation number, a user-friendly string name is used.

Alias ASM filenames, otherwise known as aliases, can be used both for referencing existing ASM files and for creating new ASM files. Alias names start with the disk group name preceded by a plus sign, after which you specify a name string of your choosing. Alias filenames are implemented using a hierarchical directory structure, with the slash (/) or backslash (\) character separating name components. You can create an alias in any system-generated or user-created ASM directory. You cannot create an alias at the root level (+), however.

When you create an ASM file with an alias filename, the file is created with a fully qualified name, and the alias filename is additionally created. You can then access the file with either name.

Alias ASM filenames are distinguished from fully qualified or numeric names because they do not end in a dotted pair of numbers. An example of ASM alias for the fully qualified filename above is:

+ dgroup2/sample/controlfile/control01.dbf

Dbvisit currently creates an ASM standby database using aliases for standby database files. If the primary database uses ASM files that do not have aliases defined for them, just FQFN, Dbvisit will prompt you to provide aliases for the standby ASM datafiles. All ASM standby database files will be created with system-generated FQFN and have aliases defined for them. Aliases for standby datafiles, tempfiles, controlfiles and redo logs will be used in the database dictionary.

To use Dbvisit to create an ASM standby database or a standby database for an ASM primary database, make sure that the operating system user that runs Dbvisit has access to Oracle executables in the ORACLE HOME for the ASM instance. Dbvisit needs execute privilege on the ASMCMD utility, and if your installation implements Oracle 11g grid infrastructure under its own home and user, you may need to add the Dbvisit user to the operating group “oinstall” to make sure it can run the ASMCMD utility.

We are hoping to have Dbvisit Standby released at the end of May 2011.

Here is a preview of the reporting capability of Dbvisit Standby version 6.0.

1. How often is Dbvisit scheduled on your primary server. For example is this every 1, 2, 5, 10, 15 or 20 minutes?
2. What type of database is Dbvisit running on? I.e. OLTP, Data Warehouse  or other?

We got a great response and would like to thank everyone who participated.

The responses (see chart below) showed that Dbvisit is scheduled on average every 12 minutes with the shortest interval reported as 2 minutes

Dbvisit is actually capable of providing a minimum of just 60 seconds data loss although this needs to be considered against how critical the database in question is and the possible subsequent impact on database performance. We would love to hear from any of our customers who schedule Dbvisit every 60 seconds or who have any queries surrounding Dbvisit scheduling, so we better understand your data availability needs.

We also found that OLTP databases are by far the most common, outnumbering all others by 2:1.

PebbleIT’s most recent sale and implementation of Dbvisit has been at QBEInsurance Australia, Australia’s largest international insurer¹ with offices in 49 countries and over 13,500 staff worldwide. QBE needed to sync their local systems to remote standby databases located offshore and chose Dbvisit because of its functionality and price.

Raymond Allo, the technical lead on the project, advised the benefits to QBE of using Dbvisit as an Oracle Data Guard alternative. “It was easy to convince QBE to utilise Dbvisit as they could clearly see the cost saving to the organisation. Some applications do not require the features of Oracle Enterprise Edition and are adequately served by Standard or Standard Edition One. Also, Dbvisit does not require changes to be made to the init.ora file like Data Guard.” He also noted that Dbvisit was effectively handling transportation of data between a primary and standby site so far apart. “There was the tyranny of distance and bandwidth to get the initial copy of the database over to the US, but after that Dbvisit is very efficient at handling the log shipping”.

PebbleIT, founded in 2003 by Managing Director Marck Moscatelli and based in Sydney Australia became a Dbvisit reseller in 2007. While the business initially focused on delivering database-related services, the strong relationships they formed with their customers meant they soon moved into providing a more diverse range of IT services as required. This includes Application and web development, consulting and Managed Services, remote DBA Support, database development and migration, and a software license advisory service.

Pebble IT’s license advisory service has seen them become the trusted advisors to their customers and help companies such as Nielsen, AMCOR and National Health and Medical Research Council not only save $100,000′s in licence costs but also significantly reduce annual maintenance fees.

PebbleIT’s commitment to providing products which allow exceptional ROI to their clients means that Dbvisit is a natural fit for the company’s ethos of value through innovation, simplicity and personalised service.

For more information about PebbleIT and their services please visit their website at www.pebbleit.com.au.

1.       As measured by gross written premium. Source: http://www.qbe.com.au/Australia/About-QBE/Insurance.html

Welcome aboard.